Week 3 Flashcards
what do you do when there is a specimen delivered to the lab without a label
-dont process
-notify clinician
- record all interactions and next steps with full name
-specimen must be verified in person
-date and time the req
-notify supervisor
-fill out IR
what do you do when the specimen was delivered to the lab without a requisition
–dont process
-notify clinician
- record all interactions and next steps with full name
-specimen must be verified in person and bring req to the lab
-notify supervisor
-fill out IR with date and time of incident
What happens when the req doesnt complete patient information
-dont process if name, identifiers or source is missing
-notify clinician and specimen with req must be verified in person
- record all interactions and next steps with full name of person taking the message
what if specimen was delivered to the lab in wrong fixative or without fixative
-process specimen as per the tests ordered
-if unknown place tissue in refrigerator
-document incident on req with date and time
-file IR
-inform pathologist on case
How is heat damage caused
pre fixation issue
-by cauterization
- occurs on margin of the biopsy
-heat will cause the CT fibers to be coagulated due to heat
-causing acidophilia
post fixation it can be caused by prolonged exposure to heat during tissue processing , heated forceps
-during embedding - prolonged heat exposure to after microtomy (hot plate or hot dry over)
what will happen if there is presence of staples and sutures
-pre fixation issue
-not pathological
-blade can be damaged during microtomy
-should be removed when visible
-if one is in a block melt the block and re embed for microtomy
what will happen if there is Cellulose contamination
pre fixation issue
-plant material in the GI tract
-cellulose from paper, cotton, and cork
-not pathological
-can damage blade during microtomy
what will happen if there is starch contamination
pre fixation issue
-when starch from gloves gets transferred on issue during specimen collection
what will happen if there is catheter damage
pre fixation issue
-epithelial tissues will be damaged/compressed easily
-if the fixation is prompt the damage stays
what what will happen if there is tattoo pigment present
pre fixation issue
-does not react with stain but many obstruct pathological areas
what will happen if there is crush artifact
pre fixation issue
-damage to fresh tissue caused by forceps
-mostly on the edge resulting in small blue cell clusters - distorted cell nuclei with intense basophilia
what will happen if there are post mortem changes - autolysis and putrefaction
Autolysis - self destruction from enzyme action- Desquamation
Putrefaction - when bacteria acts on tissue especially GI tract
pre-fixation issue
quick in areas with enzymes - gall bladder, pancreas, intestines
Intermediate - liver, kidney , spleen
slow - bones, cartilage, skin.
however there is an impact to tissues surrounding the area- if intestines autolyze quickly so do the structures around it
what will happen if there are specimen marking dyes
pre-fixation issue
-dyes are used to mark margins for orientation or cancer monitoring
-can use silver nitrate, india ink, and ink markers
-while it marks the surface it can penetrate
what will happen if there are biopsy pad or sponge artifact
pre-fixation issue
-used so small biopsies dont fall out of the cassette
-fixed tissue is placed in between two dry sponges
-can leave a sponge imprint when you try to remove the tissue for embedding seen by flattened nuclei but you can prevent this by pre soaking sponge pads in fixative or using lens paper
what will happen if there is freezing damage
pre-fixation issue
-cause frozen-thawed-fixed artifact when ice forms under tissue
-distorts nuclear and cytoplasmic components
-common after frozen sections cut
how to prevent specimen to specimen contamination
pre-fixation issue
-place left and right specimen into specific containers
-dont accession sample tissue types one after the other
-use clean scalpel blades, dissection board and other tools between specimen
what are some fixation artifacts
- Formalin pigment
- Mercuric pigment
- Streaming artifact
- Zonal fixation
how is formalin pigment formed
fixation artifacts
-caused by non buffered formalin
-pigment can be removed using picric acid or NH4OH
how is mercuric pigment formed
fixation artifacts
-by using mercury based pigment
-can remove with alcoholic iodine, then sodium thiosulphate
how is steaming artifact formed
fixation artifacts
-caused by precipitation and glycogen displacement due to fixation
-found in formalin fixed liver
how is zonal fixation formed
-when large specimen with capsules are fixed with slow penetrating fixative
-variable fixation rate
what types of issues can occur in tissue processing
- Precipitate in the chamber and in the tubing
- Poor processing
- Under-processed
- Over-dehydration
- Accidental desiccation
what causes Precipitate in the processor chamber and in the tubing
tissue processing issues
-caused by using phosphate buffered formalin as a fixative and starting dehydration at >70% alcohol
-caused when zinc-buffered formalin pH >7.0 - the pH must be below 7
–if the precipitate is in the tubing then rinse the chamber and tubing with 5-10 acetic acid
what are the causes and prevention techniques for poor processing
tissue processing issues
Causes:
-under fixation
-water remains in tissue (incomplete dehydration) leading to poor clearing and infiltration
-improper QC of tissue processor
-paraffin is contaminated by clearing agent
-too much heat during processing
Prevention
-proper fixation
-make sure the absolute alcohol hasnt absorbed water or become diluted
-use heat only for infiltration
-ensure PM is performed
what are the causes for Under-processed – tissue mushy, soft and shrunken
Incomplete hydration, clearing or infiltration
-not in fixative long enough
-faulty reagents
Evaporation of solvent that was not displaced by wax
-retraction when the tissue shrinks back into the embedded block
Troubleshoot
-re-process tissue
what are the causes for Over-dehydration – tissue dry and brittle
long time in dehydrating solutions
-causes micro chatter, parched earth , cracking and cell shrinkage
Prevention
-seperate small tissues from larger ones
-mindful of dehydration time
-decrease time in dehydration solution
what are the causes for Tissue accidentally desiccated
-caused by open processor - not used anymore in labs
-tissue can be rehydrated in water, alcohol and sodium carbonate overnight and then processed
what is floating- causes and prevention
Embedding fault
caused by:
-if tissue isnt pressed down during embedding
-need uniform surface along the base
prevention
-press down
-dont let the wax solidify at different rates
what happens when the mold is large or small
large- wax compression
small - tissue compression
prevent- get the proper mold size
what is stratification-causes and prevention
cause
uneven wax cooling
block can fall apart and cause tissue damage due to loss of support
prevention
-re embed
-fill wax properly and quickly
what will happen if Block removed from mold before it solidified
cassette will not be filled properly
-re embed and make sure block is completely cooled before you move it
what will happen if block is Underfilled -Poor support for the block
-it could detach from cassette and you could lose pt ID
cause- not enough wax
prevention - re embed and fill with appropriate amount of wax
how can transcription errors occur
-if the cassette number doesnt match the worklist
caused by
rushing
not double checking
prevention
double check
investigate
file IT
why will cracking happen on a block and how to prevent
cause:
-cold plate too cold
-wax on specimen has solidified before it could be positioned
-tissue was moved after the wax was solidifying
prevention
-check the temperature of the cold plate
-only re embed if microtomy is hard
what causes a bubble underneath the cassette - how can it be prevented
cause
-when air is trapped during embedding
prevention
-re-embed
-decrease rate of paraffin flow
-fill on an angle and then decrease the angle to displace the air before placing on cold plate
what will be caused by poor or incorrect orientation
-place tissue diagonally not parallel to mold edges
-place tissue in center
-tissues with walls (gall bladder, GIT) are embedded on edge
-tubular structures are embedded on end
-tissues with collegenous capsule must be embedded so the blade hits hard parts last - if its but first the tear can go through the sample
-multiple pieces should be placed in a diagonal line with each piece on a angle, if parallel they can cause tissue compression
if your orientation is incorrect from the gross what will it cause and how can you prevent it
cause
-wrong side was inked
prevention
-embed correct side
-complete checklist properly
-open GI tract layers before grossing to avoid rolling because that makes it hard to see layers
how is soft mushy tissue caused and how do you prevent it
cause
tissue grossed too thick
tissue was under processed
CA
reprocess
gross the tissue thinly
what causes tissue carryover and how to prevent
cause
fragmented tissues that contaminate the next sample
-forceps metastasis
CA
-clean your forceps between cassettes
-one cassette at a time
what causes pieces/tissues to be missing from the cassette and how to prevent
Cause
-lost during processing
-small pieces were not put in filter paper and were missed
CA
-note the number of pieces during grossing
-check back of cassette before discarding
- check bottom of tissue processor
-open filter paper or biopsy bags slowly
-notify supervisor and file IR if anything is out of place
-if you cannot find the tissue embed the empty cassette and notify the pathologist
